Health problems due to allergies have been increasing recently. The allergy to house dust plays a particularly large role here. This is caused by the excrements of the house dust mite, which contains allergens and form extremely fine dust aerosols. The occurrence of the house dust mites is more and more frequently observed in the industrial countries. Possible causes of this are the microclimate in dwelling rooms and the decrease in natural enemies of the house dust mites as the result of hygienic measures such as, for example, vacuum-cleaning. House dust mites live wherever they can hide and where they find suitable nourishment and a microclimate suitable for them with respect to atmospheric humidity and warmth. The result is that textile materials represent their preferred places of stay, that is to say, beds, upholstered furniture, carpets and the like.
There are so far no satisfactory agents for controlling house dust mites. Due to their composition, the known agents are suitable only for the treatment of small areas such as, for example, the mattresses of beds. They are applied by spraying the surface. However, a closer investigation shows that the treatment of beds--even if it should be effective there--can solve only a part of the problem. Upholstered furniture which, as a rule, is less frequently and less intensively cleaned than beds, is in many cases heavily infested. Moreover, very fine dust is continuously whirled up from carpets as the result of walking on them; this means that allergic persons are troubled day and night.
The tendency of the house dust mite to hide and to creep under such objects has the result that a treatment of the surfaces of the said interior furnishings is not sufficient. A carpet must be treated right in the depth, and mattresses and upholstered furniture must be treated in a layer of 1 to 2 cm thickness, where the majority of the mites are present.
On the other hand, a preparation (agent) which is intended to be capable of destroying house dust mites must be physiologically compatible with and toxicologically acceptable to humans who are nearby.